KN6 Krytron tube testing

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Andrew Seltzman
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KN6 Krytron tube testing

Post by Andrew Seltzman » Sat Apr 08, 2017 11:49 pm

I recently acquired some KN6 and KN6B krytron tubes and have begun testing them

Pictures of the KN6
SAM_5923a.jpg
SAM_5901a.jpg
SAM_5914a.jpg
SAM_5915a.jpg
Closeups with a digital microscope
Still0003a.jpg
Still0002a.jpg
Still0001a.jpg
Keep alive plasma
SAM_5931a.jpg
Voltage waveforms were measured with a tektronix TDS3034B oscilloscope and P6015A high voltage probes. The krytron was connected to a 20nF 2kv capacitor charged through a 1M resistor, the keep alive was connected through a 25M resistor, the trigger was capacitivly coupled to the trigger transformer from an SSY-1 laser and connected to the anode with a 100k resistor, and the load was a 1ohm resistor.

Discharges recorded with a high speed camera
keepalive 1 frame before firing
keep-alive.png
Firing
firing.png
scope trace, ch1 is trigger pulse, ch4 is voltage across capacitor, all x1000
krytron-test.png
the tube achieves ~200ns delay time(typical of the kn6) and almost no jitter, there is some ringing due to stray inductance in the circuit.

Datasheets and krytron circuits
pulse-tubes1.zip
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Andrew Seltzman
www.rtftechnologies.org

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Richard Hull
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Re: KN6 Krytron tube testing

Post by Richard Hull » Sun Apr 09, 2017 8:12 pm

I have 3 or 4 KN6 Krytrons they are commonly used in certain laser system triggers where precise firing is needed. Due to their application as special bomb triggers they are considered "dual use" devices and are export controlled. The Sprytron is a pico second delay trigger and I do not think they are commonly available. Both the krytron and sprytron are capable of massive currents but the life span for the krytron is under 1000 firings at its limit. Lighter currents will extend its life span.

The sprytron, by desgn application, is typically a one shot consumable.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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